Start the countdown clock. NFL teams have less than six months to discover a way to block the Rams’ dominating defensive duo of Ndamukong Suh and Aaron Donald.

That nightmare pair became a reality Monday for the Rams, who signed Suh, one of the league’s most disruptive defensive linemen of the past decade, to a one-year contract. ESPN reported that the contract is worth $14 million.

The Rams might now have the NFL’s best defense, even though they’ve yet to finalize their group of linebackers. It’s also not certain where exactly Suh will play on the defensive line, but it doesn’t particularly matter. Suh, Donald and Michael Brockers likely will terrorize opposing offenses.

In coordinator Wade Phillips’ 3-4 system, Suh could line up opposite Donald at end, with Brockers in the middle, or the Rams could give Suh, listed at 6-foot-4, 305 pounds, a look at nose tackle.

Either way, the Rams, who presumably started this offseason in search of a moderate upgrade on their defensive line, got a massive one in Suh, who turned 31 in January. Suh has yet to miss a game because of injury in eight NFL seasons and is a former (and multi-year) All-Pro and Pro Bowl selection.

Suh, who has 51.5 career sacks, became available last week when the Miami Dolphins released him, halfway through the record-setting six-year, $114-million contract he signed in 2015.

Suh played well in Miami, and had 4.5 sacks and two forced fumbles last season, but the contract turned cost-prohibitive — Suh would have carried a salary-cap hit of $26.1 million in 2018 — so the Dolphins released Suh, who made free-agent visits to Tennessee and New Orleans last week and also entertained a contract offer from the New York Jets, who later rescinded it.

The Rams’ pitch, delivered last week at the team’s practice facility in Thousand Oaks, seemed obvious. The Rams, in 2017, won the NFC West with one of the NFL’s most dynamic offenses and a defense that, in most statistical categories, performed only slightly above average.

A major shakeup has taken place over the past month, as the Rams have brought in cornerbacks Aqib Talib, Marcus Peters and Sam Shields to create would should be a much-improved secondary.

Now, with Suh, the Rams’ defense arguably is as strong as their offense, and the Rams figure to be on short lists for Super Bowl contenders in 2018. The Rams, given their salary structure, couldn’t offer Suh a big-money, long-term contract, but they could offer him a chance to win his first championship.

Suh, the No. 2 overall pick of the 2010 draft, now joins Donald, last season’s NFL Defensive Player of the Year, and Brockers, who recorded 4.5 sacks in a stellar 2017 season.

The pairing, presumably, will be a short-term one. The Rams still must sign Donald, who is in the final year of his rookie contract, to a new deal, which likely will be massive. Suh’s signing, on both sides, is a short-term boost for the Rams, and could help Suh sign another big contract after the 2018 season.

The Rams’ defensive line also includes Dominique Easley and Ethan Westbrooks, who still faces one misdemeanor count of carrying a loaded firearm based on his arrest last September in Kern County.

Suh has no history of off-field issues but is known for on-field aggression that sometimes crosses a line. Suh has been fined by the league eight times in eight seasons and received a two-game suspension in 2011 after he stomped on the arm of Green Bay offensive lineman Evan Dietrich-Smith.

Suh had one incident last season, when he grabbed at the throat of Baltimore quarterback Ryan Mallett during a minor scuffle, but Suh did not receive any discipline from the league.

For all his individual success, including All-Pro selections in 2010, 2013 and 2014, and a Pro Bowl selection as recently as 2016, Suh has yet to win an NFL playoff game. He went 0-2 with the Lions and 0-1 with the Dolphins and also has yet to play on a team that has won its division.

The Rams, presumably, now will turn their attention on defense to linebacker, after the recent trades of veterans Alec Ogletree and Robert Quinn.

Mark Barron is the only returning starter at the moment, although the Rams continue to talk with free agent Connor Barwin. Two of last season’s primary backups, Cory Littleton and Samson Ebukam, are expected to step into bigger roles in 2018. The Rams also figure to build depth during the draft.

On offense, the Rams still could look — either through the draft or free agency — to add to their depth at receiver and on their offensive line.

Rich Hammond was a high school senior when the Rams left town in 1995, and now he's their beat writer for the Southern California News Group. A native of L.A., Rich broke in at the Daily Breeze as a college freshman and also has covered USC, the Kings, the Lakers and the Dodgers. He still loves sports and telling stories. Don't take the sarcastic tweets too seriously.